The prior art is exemplified by U.S. Pat. Nos. 103,085; 118,987; 950,455; 1,212,196; 2,075,768; 2,523,626; 2,877,599; 2,940,942; 3,050,424; 3,630,710; 3,649,239; and 3,832,220; British Pat Nos. 2,003; 27,257; and 350,398; and an article entitled "SEAWEED AS A FERTILIZER" by Ernest Booth appearing in the June 1953 issue of "Organic Gardening" at pages 14-17.
In the process of extracting agar, sodium alginate, carrageenin, and other products from seaweed, various forms of filter cake are produced which are normally discarded and added to the pollution of the environment. Many localities have now forbidden the dumping of such filter cake which are regarded as pollutants and refuse. The present invention not only makes use of such filter cake, but also develops new techniques for obtaining such filter cake and the products formed therefrom.